Researchers have found that current or past use of methamphetamine or other stimulants may lead to psychomotor control deficits, or a reduced ability to control physical movement.

Study participants were asked to hold their dominant arm in various positions, one at a time, and maintain each position for 60 seconds, with a 30-second rest between each. Investigators found impairments in terms of both tremor and arm-droop in heavy stimulant users. Tremor, but not arm-droop, persisted for at least 18 months following withdrawal from stimulant use.

 

Source: WileyFull bibliographic information:
Psychomotor Tremor and Proprioceptive Control Problems in Current and Former Stimulant Drug Users: An Accelerometer Study of Heavy Users of Amphetamine, MDMA, and Other Recreational Stimulants. The Journal of Clinical Pharmacology.